Merge branches 'tracing/doc', 'tracing/ftrace', 'tracing/printk' and 'linus' into...

[linux-2.6-omap-h63xx.git] / arch / x86 / mm / pageattr.c

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 8ca0d8566fc826cb8f7f42b05133c4498da59e64..8253bc97587e4950e2c2ea3170da767245ac825f 100644 (file)
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -482,6 +482,13 @@ static int split_large_page(pte_t *kpte, unsigned long address)
        pbase = (pte_t *)page_address(base);
        paravirt_alloc_pte(&init_mm, page_to_pfn(base));
        ref_prot = pte_pgprot(pte_clrhuge(*kpte));
+       /*
+        * If we ever want to utilize the PAT bit, we need to
+        * update this function to make sure it's converted from
+        * bit 12 to bit 7 when we cross from the 2MB level to
+        * the 4K level:
+        */
+       WARN_ON_ONCE(pgprot_val(ref_prot) & _PAGE_PAT_LARGE);
 
 #ifdef CONFIG_X86_64
        if (level == PG_LEVEL_1G) {
@@ -508,18 +515,13 @@ static int split_large_page(pte_t *kpte, unsigned long address)
 #endif
 
        /*
-        * Install the new, split up pagetable. Important details here:
-        *
-        * On Intel the NX bit of all levels must be cleared to make a
-        * page executable. See section 4.13.2 of Intel 64 and IA-32
-        * Architectures Software Developer's Manual).
+        * Install the new, split up pagetable.
         *
-        * Mark the entry present. The current mapping might be
-        * set to not present, which we preserved above.
+        * We use the standard kernel pagetable protections for the new
+        * pagetable protections, the actual ptes set above control the
+        * primary protection behavior:
         */
-       ref_prot = pte_pgprot(pte_mkexec(pte_clrhuge(*kpte)));
-       pgprot_val(ref_prot) |= _PAGE_PRESENT;
-       __set_pmd_pte(kpte, address, mk_pte(base, ref_prot));
+       __set_pmd_pte(kpte, address, mk_pte(base, __pgprot(_KERNPG_TABLE)));
        base = NULL;
 
 out_unlock: